Baby’s skin? Anyone else??

Does anyone else’s baby’s skin go all veiny sort of looking? My boys skin very often just has all these red lines traced all over his skin and I don’t know why 🤔

He’s 6 weeks old, had it ever since he’s been born. Midwives said it was fine but never told me why his skin is like that...

Pretty sure I used to get it when I was cold though... TIA